The present invention relates generally to fuel supply systems for motor vehicles.
More specifically, the invention concerns a filler pipe unit for the fuel tank of a motor vehicle, including a substantially rigid fuel inlet pipe having a first end attachable to the motor vehicle body and a second end for connection to the fuel tank, and a vent pipe integral with the fuel inlet pipe and joined thereto between the said first and second ends, and intended also to be connected to the fuel tank.
Known filler pipe units of the kind described above have the advantage that they facilitate the operations for installation in a motor vehicle as they are relatively rigid and require few fixing elements to hold them in position to define a predetermined path within the vehicle body. In accordance with regulations which limit maximum emissions of hydrocarbon gases into the environment, a chamber for collecting the fuel vapours is associated with these known units, which typically functions as an expansion vessel and an accumulator for the vapours. This chamber, which is manufactured separately from the filler pipe unit, must however be attached to the motor vehicle and this necessitates the definition of a zone within the motor vehicle for its anchorage together with associated connection elements, the presence of which means that installation of the fuel supply system takes longer and is generally more labourious.